+ const struct proto_abbrev *p;
+
+ /* Use a "switch" statement for single-bit names so that we get a compiler
+ * warning if we forget any. */
+ switch (protocol) {
+ case OFPUTIL_P_NXM:
+ return "NXM-table_id";
+
+ case OFPUTIL_P_NXM_TID:
+ return "NXM+table_id";
+
+ case OFPUTIL_P_OF10:
+ return "OpenFlow10-table_id";
+
+ case OFPUTIL_P_OF10_TID:
+ return "OpenFlow10+table_id";
+ }
+
+ /* Check abbreviations. */
+ for (p = proto_abbrevs; p < &proto_abbrevs[N_PROTO_ABBREVS]; p++) {
+ if (protocol == p->protocol) {
+ return p->name;
+ }
+ }
+
+ return NULL;
+}
+
+/* Returns a string that represents 'protocols'. The return value might be a
+ * comma-separated list if 'protocols' doesn't have a simple name. The return
+ * value is "none" if 'protocols' is 0.
+ *
+ * The caller must free the returned string (with free()). */
+char *
+ofputil_protocols_to_string(enum ofputil_protocol protocols)
+{
+ struct ds s;
+
+ assert(!(protocols & ~OFPUTIL_P_ANY));
+ if (protocols == 0) {
+ return xstrdup("none");
+ }
+
+ ds_init(&s);
+ while (protocols) {
+ const struct proto_abbrev *p;
+ int i;
+
+ if (s.length) {
+ ds_put_char(&s, ',');
+ }
+
+ for (p = proto_abbrevs; p < &proto_abbrevs[N_PROTO_ABBREVS]; p++) {
+ if ((protocols & p->protocol) == p->protocol) {
+ ds_put_cstr(&s, p->name);
+ protocols &= ~p->protocol;
+ goto match;
+ }
+ }
+
+ for (i = 0; i < CHAR_BIT * sizeof(enum ofputil_protocol); i++) {
+ enum ofputil_protocol bit = 1u << i;
+
+ if (protocols & bit) {
+ ds_put_cstr(&s, ofputil_protocol_to_string(bit));
+ protocols &= ~bit;
+ goto match;
+ }
+ }
+ NOT_REACHED();
+
+ match: ;
+ }
+ return ds_steal_cstr(&s);
+}
+
+static enum ofputil_protocol
+ofputil_protocol_from_string__(const char *s, size_t n)
+{
+ const struct proto_abbrev *p;
+ int i;
+
+ for (i = 0; i < CHAR_BIT * sizeof(enum ofputil_protocol); i++) {
+ enum ofputil_protocol bit = 1u << i;
+ const char *name = ofputil_protocol_to_string(bit);
+
+ if (name && n == strlen(name) && !strncasecmp(s, name, n)) {
+ return bit;
+ }
+ }
+
+ for (p = proto_abbrevs; p < &proto_abbrevs[N_PROTO_ABBREVS]; p++) {
+ if (n == strlen(p->name) && !strncasecmp(s, p->name, n)) {
+ return p->protocol;
+ }
+ }
+
+ return 0;
+}
+
+/* Returns the nonempty set of protocols represented by 's', which can be a
+ * single protocol name or abbreviation or a comma-separated list of them.
+ *
+ * Aborts the program with an error message if 's' is invalid. */
+enum ofputil_protocol
+ofputil_protocols_from_string(const char *s)
+{
+ const char *orig_s = s;
+ enum ofputil_protocol protocols;
+
+ protocols = 0;
+ while (*s) {
+ enum ofputil_protocol p;
+ size_t n;
+
+ n = strcspn(s, ",");
+ if (n == 0) {
+ s++;
+ continue;
+ }
+
+ p = ofputil_protocol_from_string__(s, n);
+ if (!p) {
+ ovs_fatal(0, "%.*s: unknown flow protocol", (int) n, s);
+ }
+ protocols |= p;
+
+ s += n;
+ }
+
+ if (!protocols) {
+ ovs_fatal(0, "%s: no flow protocol specified", orig_s);
+ }
+ return protocols;